The invention relates to an electrical drive unit for a motor vehicle with a wheel hub drive, in particular, a wheel hub motor, driving a vehicle wheel.
On order for an electrical drive unit having a wheel hub drive to meet the requirements for service life common in the automotive industry, the wheel hub drive must have a corresponding seal. Here, the fact that temperatures between −30° C. and +50° C. can occur in the interior of a wheel hub drive depending on the time of year, weather, and operating state, is problematic. If the wheel hub drive is sealed hermetically with regard to the surroundings with a conventional seal, a greatly increased inner pressure builds up in the interior of the wheel hub drive due to heating during the operation of the wheel hub drive, which could lead to the result that the air enclosed in the wheel hub drive can lift the sealing lips of a sealing element provided for sealing and can generate an at least partial pressure equalization to the outside. During the subsequent standstill phase of the wheel hub drive, the wheel hub drive cools down, the air in the interior of the wheel hub drive contracts, and a lower pressure builds up relative to the surrounding outside the wheel hub drive. If this lower pressure becomes too large, the sealing element can allow air to penetrate via the sealing lips from the surroundings into the interior of the wheel hub drive, so that the wheel hub drive “breathes.” This has the effect, for one, that the sealing friction and thus the wear of the sealing element is increased when, during the pressure equalization, an increased contact force acts on the sealing lips of the sealing element. Second, foreign bodies or liquids, such as water, can be transported into the interior of the wheel hub drive when air is led through the opened sealing lips. This can lead to damage both on the wheel hub drive itself and also on the active sealing surface of the sealing element of the wheel hub drive.